XP601 Summary H. W. Kugel 5/08/06
XP 601 Summary for Thurs 5/ 04/06 Goal: Observe an effect • A comparison discharge was developed with low LFS fueling ( Inj2=11.5 TorrL and SGI=9.75 TorrL). • 6 Ohmic He Conditioning discharges were applied to condition the walls • 378 mg of lithium were evaporated. This was measured to be 477 A° on the BayH QDM. • 120474, the first 1 MW D NBI ref shot following lithium deposition Exhibited: • 29% decrease in density relative to 464, • Peakedness change from 3.5 to 3.9, • Electron temp of 2 KeV for 1 MW, • Taue ~ 90 ms. • Xeus OVIII was the same for 474 but decreased for 475 and went to zero for the following 3 NBI shots.
XP 601 Summary for Thurs 5/ 04/06 (Cont) • On the next shot (475) the density reverted to that of the comparison shot but the some peakedness remained. • After 476 HeGDC started being applied between discharges but the density could not be lowered below that of 464. • An ohmic HeCond shot (482) was applied to attempt to test the effect of graphite pumping. 483, D NBI exhibited about a 10% decrease in density. • Then 2 He Cond shots (484,485) were applied and the following ref shot showed a much smaller change (~5%). • The last 2 shots were used to reduce the outside gas fueling to zero and replace with SGI fueling for lower density.
XP 601 Summary for Fri 5/ 05/06 Goal: a) Verify reproducibility of the effect b) Determine the relative graphite and Li contributions • Additional comparison discharge development was performed. • A reference discharge was performed before starting He Conditioning • 6 Ohmic He Conditioning discharges were applied to condition the walls • The ref discharge was applied an exhibited ~ 14% decrease in density. • A lithium evaporation was attempted but a snout heater malfunction occurred
• Near Term Plan • • Remove LITER1B from vessel (Wed morning) • • Investigate replacing cartridge with either • • either new cartridge (2.5 wks) • • or use cartridge 1C from L-245 (without air cooled shroud) • • Investigate increasing aiming angle from 22° *CS shoulder to ~16° (CS bottom) • • Issues • • The Heater vendor suggests derating the max power by x4 (165 w to 660w) • for vacuum service • • Building new cartridge with upgraded heaters will require testing • • Using Cartridge 1C without air-cooled shroud will cause local vessel • heating and outgassing • • Changing the aiming angle may not be possible during this Maintenance Week